JP2023098508A - Steel pipe installation device, and steel pipe installation method - Google Patents

Abstract

To provide a steel pipe installation device which can efficiently and safely install a steel pipe.SOLUTION: A steel pipe installation device has: an excavation shaft member 3 having an excavation bit 2 at its tip; a rotary drive device 5 for rotating the excavation shaft member 3; and a cylindrical earth removal member 7 having substantially the same diameter as that of a steel pipe P to be installed. The cylindrical earth removal member 7 has: an earth removal port 71 for removing excavation muck blown up through the steel pipe P to be installed; a connection part 75 for attachably/detachably connecting the cylindrical earth removal member 7 to/from the upper part of the steel pipe P to be installed; and a stopper 77 for securing a rotational reaction force during operation of the rotary drive device, for the steel pipe P. The steel pipe installation device having such a structure dispenses with troublesome work such as extension and separation of a plier, dispenses with extension of the excavation shaft member associated with the extension of the plier, and can efficiently and safely install the steel pipe.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to a steel pipe driving device used for driving steel pipes using an excavation shaft member, and a steel pipe driving method using this device. Specific examples of steel pipes to be driven include steel pipe piles, steel pipe sheet piles, casings, and the like.

When driving steel pipes such as steel pipe piles, the driving work is performed using, for example, a rotary impact press-in method using a down-the-hole hammer. Patent Literature 1 (Japanese Unexamined Patent Application Publication No. 2017-193930) discloses the principle of rotational impact press-fitting of a steel pipe pile using a down-the-hole hammer.

(Principle of placing steel pipes)
5 and 6 show the principle of rotary impact press-fitting of steel pipe piles using a down-the-hole hammer.
FIG. 5 is a schematic diagram showing the principle of rotational impact press-fitting of a steel pipe pile using a down-the-hole hammer.
FIG. 6 is a detailed diagram (left side of FIG. 6) showing the principle of rotary impact press-fitting of a steel pipe pile by a down-the-hole hammer, and a plan view (right side of FIG. 6) showing the engagement relationship between the steel pipe pile and the lead material that are press-fitted by rotary impact. be.

As shown in FIG. 5, the steel pipe driving device used for driving the steel pipe pile P mainly consists of a crane-suspended rotary drive device 81 and an excavation shaft member 82 (a drill rod) connected to the rotary drive device 81. )have.

The rotary drive device 81 rotates an excavating shaft member 82 thereunder. Under the rotary drive device 81, a substantially cylindrical earth discharge cap 87 functioning as earth discharge path control means is provided. This earth removal cap 87 is fixed to the lower end of the rotary drive device 81 so as to surround the upper portion of the excavation shaft member 82, as shown in FIG. Between the outer peripheral surface of the excavating shaft member 82 of the steel pipe placing device and the inner peripheral surface of the earth removal cap 87, there is a gap for discharging the excavation muck blown up by the air lift.

As shown in FIG. 6, the excavating shaft member 82 is provided with a down-the-hole hammer 83 having a built-in piston for generating an impact pressure force. The excavation shaft member 82 is operably connected to the rotary drive device 81 through the inner side of the cylindrical portion of the earth removal cap 87 .

On the other hand, at the lower end of the excavation shaft member 82 equipped with the down-the-hole hammer 83, an expandable excavation bit 85 for excavating the ground is provided. As shown in FIG. 6, an overhang portion 84 (steel pile side casing An engaging portion that collides with the top P1 in the vertical direction) is fixed.

A drilling bit 85 at the lower end of the steel pipe driving device is configured to be displaceable (that is, expandable and retractable) between an expanded state and a reduced diameter state. When the excavation bit 85 is in a diameter-reduced state, the excavation bit can be freely inserted into and removed from the steel pipe pile P. In the expanded state, the excavation bit 85 protrudes outward, and the turning locus of its outer end exceeds the outer diameter of the steel pipe pile P. As shown in FIG.

When driving the steel pipe pile P, as shown in FIG. 5, an excavation shaft member 82 is inserted into the hollow portion of the steel pipe pile P, an excavation bit 85 is protruded from the tip opening, and the excavation bit is set in an expanded state. and excavate the target ground.

When the steel pipe pile P is driven using the steel pipe driving device configured as described above, the rotation drive device 81 applies a rotational force to the excavation shaft member 82, and at the same time, the compressor drives the down-the-hole hammer 83 with compressed air (compressed air). air). When compressed air is supplied to the down-the-hole hammer 83, the piston built in the down-the-hole hammer 83 is driven up and down, and the striking force of the piston is transmitted to the drilling bit 85 at the tip of the hammer. As a result, impact excavation can be continuously performed on the ground to be excavated while rotating.

On the other hand, the driving air (compressed air) supplied toward the down-the-hole hammer 83 not only drives the down-the-hole hammer, but also generates an air lift effect inside the steel pipe pile P, and excavation that is cut out by the excavation bit 85. The muck (excavated soil) is blown up with air. That is, the excavated muck (excavated soil) scraped out by the excavation bit 85 is blown up in an air-lift manner by the airflow derived from the driving air (compressed air) of the down-the-hole hammer 83, as indicated by the arrow in FIG.

The excavation mud blown up by the airlift effect is, as indicated by the arrow in FIG. through a path consisting of gaps in the steel pipe pile P, and is discharged from the upper end opening of the steel pipe pile P, and is further discharged to the outside through the discharge port of the earth discharge cap 87 positioned so as to cover the steel pipe pile P. be done.

By performing rotational impact excavation on the target ground based on the above-described principle, the steel pipe driving device excavates while ejecting excavation mud from the upper side of the steel pipe pile. As shown in FIG. 6, when the steel pipe driving device excavates, the projecting portion 84 fixed to the outer peripheral surface of the drilling bit 85 and below the down-the-hole hammer 83 and the lower end side inner wall side of the steel pipe pile P Casing top P1 (protruding part/shoe ring) fixed to and interfere with each other in the vertical direction (mutually collide with each other), and the steel pipe pile P is impact-press-fitted in the excavation direction.

Therefore, when the ground is excavated with the drilling shaft member 82 of the steel pipe driving device inserted into the steel pipe pile P, the impact force is applied to the lower part of the steel pipe pile at the same time, and the steel pipe pile P is driven into the steel pipe. Since it follows the equipment, impact press-fitting of the steel pipe pile progresses at the same time as excavation.

(Conduit material used for placing steel pipes)
Since the driving principle of the steel pipe pile described above utilizes the rotational force of the rotational drive device, it is necessary to secure the rotational reaction force (reaction force source of the rotational force) of the rotational drive device 81 . If the rotational reaction force of the rotary drive device 81 cannot be ensured, it is not possible to apply a rotational force to the tip of the excavation shaft member 82 (excavation bit 85). Therefore, Patent Document 2 (Japanese Unexamined Patent Application Publication No. 2000-080876) discloses means for securing the rotational reaction force of the rotary drive device, as shown on the right side of FIG. That is, in the conventional technology, the guiding material G (guide frame) that guides the steel pipe pile P to be driven while preventing rotation, and the rotation suppressing member P3 (bar-shaped engaging member) fixed to the outer peripheral surface of the steel pipe pile P are using.

As shown in the right side of FIG. 6, the guiding material G (guide frame) in the prior art includes a space capable of guiding the steel pipe pile P to be driven in a predetermined direction, and a rotation suppressing member protruding on the outer peripheral surface of the steel pipe pile P. It has a concave portion G3 (engagement portion) into which P3 (bar-shaped engagement member) is fitted. The elongated rotation restraint member P3 of the steel pipe pile P is welded onto the outer peripheral surface of the steel pipe pile P along the longitudinal direction. When driving the steel pipe pile P, the rotation suppressing member P3 protruding on the side surface of the steel pipe pile P is fitted in the recess G3 of the guide material G (the rotation suppressing member P3 of the steel pipe pile P is in the guide material G The steel pipe pile P is guided in the driving direction by the guide material G while maintaining the state of sliding engagement with the recess G3.

By driving the steel pipe pile P using the guide material G having such a function, the steel pipe pile P can be guided in the driving direction without being removed from the design position (pile center). The rotation-stopped state of the pile P can be reliably maintained, and the rotational force of the rotation drive device 81 can be reliably applied to the excavation shaft member 82 . Stoppers are protrudingly provided on the outer peripheral surface of the upper portion of the steel pipe pile P to be driven and the inner peripheral surface of the earth removal cap 87 surrounding it. By matching, the rotational reaction force secured by the guide material can be reliably transmitted to the rotation drive device 81 via the steel pipe pile P and the soil removal cap 87 .

(Steel pipe placement process using lead material)
FIG. 7 shows an example of a process for placing steel pipes using the guide material G described above. A steel pipe pile is given as an example of steel pipes. In the process illustrated in FIG. 7, the top end of the design pile is positioned lower than the ground level (surface on which the guide material G is installed), and the top end of the steel pipe pile P to be driven reaches the top end of the design pile shown in the figure. It is assumed that piles will be driven.

As shown in FIG. 7(a), in the step of driving the steel pipe pile P, first, the drilling shaft member 82 of the steel pipe driving device is inserted into the hollow portion of the steel pipe pile P, and the drilling bit Extend 85 to set the drilling bit in the expanded state. The guide material G is installed on the ground at a position higher than the top of the design pile. In this state, the steel pipe driving device is suspended by a crane, the steel pipe pile P is passed through the guide space of the guide material G, and the excavation bit 82 is set at the center of the pile.

Next, as shown in FIG. 7(b), driving of the steel pipe pile P through the guide material G is advanced by using both rotary excavation by the rotary drive device and impact press-fitting by the down-the-hole hammer. During the process of rotary excavation and impact press-fitting, as shown on the right side of FIG. The steel pipe pile P is guided in the driving direction along the center of the pile by the guide material G while maintaining the mating state.

As the impact press-fitting of the steel pipe pile P progresses, the top end of the steel pipe pile P approaches the guide material G. If the impact press-fitting of the steel pipe pile P proceeds as it is, the lower end of the soil discharge cap 87 surrounding the upper outer peripheral surface of the steel pipe pile P collides with the guide material G, so that the impact press-fitting of the steel pipe pile P cannot proceed any further. The steel pipe pile P can pass through the guide space of the guide material G, but the soil discharge cap 87 having a larger diameter than the steel pipe pile P cannot pass.
In addition, when the crown of the steel pipe pile P being driven passes through the guide material G and the steel pipe pile P separates from the guide material G, it becomes impossible to ensure the rotational reaction force in the guide material G, and the steel pipe The pile P cannot be guided by the guide material G.

Therefore, in the prior art, before the lower end of the earth removal cap 87 reaches the guide material G, as shown in FIG. Yatsuko Y is added to the head of P by welding. Yatko Y is a tubular member (dummy pipe) having the same diameter as the steel pipe pile P, and, like the steel pipe pile P, has a rotation restraining member (bar-shaped engaging member) that fits into the recess G3 of the guide material G. ing. That is, Yatco Y is designed to have substantially the same cross-sectional shape and dimensions as the steel pipe pile P.

As shown in FIG. 7(c), when the addition of the Yatsuko Y to the head of the steel pipe pile P in the process of driving is completed, an excavation shaft member 82 having approximately the same length as the length of the added Yatsuko is added. As shown in FIG. 7(d), the drilling shaft member 82 of the steel pipe driving device is inserted again into the inner hollow portion of the steel pipe pile P, and the drilling bit 85 is protruded from the tip opening of the drilling bit to expand the diameter of the drilling bit. set to state. Then, driving of the steel pipe pile P through the guide material G is resumed by using both rotary excavation by the rotary drive device and impact press-fitting by the down-the-hole hammer.

If the impact press-fitting of the steel pipe pile P proceeds as it is, the top of the steel pipe pile P will pass through the guide material G. Even after passing through the guide material G, the rotation suppressing member fixed to the outer peripheral surface of the guide material G remains fitted in the recess G3 of the guide material G, and the guide material G pushes the steel pipe pile P through the guide material Y. It will guide you in the casting direction.

Then, as shown in FIG. 7( e ), when the top end of the steel pipe pile P reaches the design pile top end, the steel pipe driving device is pulled out from the steel pipe pile P. Subsequently, the Yatsuko Y is separated from the head of the steel pipe pile P that has been placed and removed.

This completes the driving of steel pipe piles.

JP 2017-193930 A JP-A-2000-080876

In general, yattoko, which are temporary piles made of steel pipes, are used to drive the pile heads of driven piles and hollowed piles into the ground or into water.
In recent years, rotary impact excavation of steel pipe piles and steel pipe sheet piles using an expanding down-the-hole hammer has become popular, and Yatco is expected to have advanced functions different from the conventional It's becoming
For example, in order to discharge excavated soil with an air lift, it is necessary to keep the cross-sectional area of the air passage constant in order to maintain the pressure of the compressed air that drives the down-the-hole hammer. If the pile head lowers, the air will dissipate and the pressure will drop, making it impossible to blow up the excavated soil to a predetermined height, which may interfere with excavation.
In addition, in the case of hanging construction using a crane, etc. (construction without using a leader of a pile driver), the head of the steel pipe pile may be placed above the ground or water surface and rotated during the driving of the steel pipe pile. (which is the source of the reaction force), it becomes impossible to secure the rotational reaction force to the guide material, and it becomes impossible to guide the steel pipe pile with the guide material. Therefore, in the prior art, as shown in FIG. 7(c), a method of adding yattko to the head of the steel pipe pile is adopted.

However, in the above method, one yattko is required above the ground surface, the water surface, the guide material, etc., to keep the pile head of the steel pipe pile substantially high when the pile driving is completed, which is uneconomical. there were.

In addition, it takes a lot of time and effort to replenish the yattco during or before placing the steel pipe pile, and to separate the yatco after placing the pile, which lacks safety and hinders the shortening of the construction period.

In addition, as a measure to shorten the critical path of the process, in order to save the trouble of adding the yattco during the construction work, lengthen the target steel pipe pile by the length of the yattco (for example, at the order (procurement) stage of the steel pipe pile There are methods such as forming a steel pipe pile with a length that includes the length, or welding the length of the yattco on site as a separate parallel process before placing work), but even in that case, There is still the problem that the lengthened steel pipe piles waste material, which is uneconomical.
Therefore, in any case where YATCO is integrated with the pile, it is necessary to separate YATCO, which is not necessary for the pile driving process for the original design length, and the accompanying work, which makes the process more efficient and saves resources. was sought.

In addition, in the conventional steel pipe placing equipment, there is a gap between the head of the steel pipe to be placed and the earth discharge cap surrounding it, which allows air to pass through. Compressed air leaks through this gap, weakening the momentum of the air lift, and there is a problem that the excavation muck is prevented from being discharged by the air lift.

Therefore, in view of the above-mentioned problems of the prior art, the object of the present invention is to improve the structure of guide materials, construction jigs, or construction objects for the convenience of driving piles in the ground or in water, or for other construction purposes. When steel pipes are driven in a state where an object such as a part of the To provide a steel pipe placing device and a steel pipe placing method using the device, which enable the steel pipes to be placed efficiently without relying on uneconomical means such as gas cutting. be.

Another object of the present invention is to provide a steel pipe placing apparatus capable of efficiently discharging excavated debris in the steel pipe placing using an excavation shaft member, and a steel pipe using this apparatus. To provide a casting method.

The above purpose is
an excavation shaft member having a length approximately equal to at least the length of the steel pipe plus the length of the yattco;
a drilling bit provided at the tip of the drilling shaft member;
a rotary drive device for rotating the drilling shaft member;
a cylindrical earth removal member provided under the rotary drive device so as to surround an upper portion of the excavation shaft member;
The cylindrical earth removal member is
It has a length that is at least approximately equal to the length of Yatko,
a connection part for detachably connecting the cylindrical earth removal member to the upper part of the steel pipes to be placed;
An excavation port for discharging excavated mud blown up through the steel pipes to be placed,
is achieved by a pipe placing device having

In the steel pipes placing apparatus, the cylindrical earth removing member is preferably configured to have, for example, substantially the same diameter as the steel pipes to be placed.

In the above-mentioned steel pipe driving device, the connecting part of the cylindrical earth removal member serves as a discharge route for the excavated soil and for supplying the rotational reaction force of the driving device for achieving the purpose of driving the pile and excavating the inside of the pipe accompanying it. As long as it is a connection between a cylindrical member and steel pipes for realizing various functional linkages such as the feasibility as a material, various modes such as butt, fitting, engagement, and joining are appropriately used depending on the purpose. Good to be selected.
For example, it has a telescoping connection structure that can be connected to the top of steel pipes to be placed.

Further, in the above steel pipe placing apparatus, the steel pipe has, for example, rotation restraining means for restraining rotation of the steel pipe by engaging with the engaging portion of the guide material. Furthermore, in this case, the cylindrical earth removing member of the steel pipe placing device has a rotation restraining means that engages with, for example, the engaging portion of the guide material to restrain the rotation of the cylindrical earth removing member.

Further, the cylindrical earth removing member has a stopper for fixing the position of the steel pipes and the rotary drive device in the rotational direction of the steel pipes placing device in the connected state with the steel pipes. .

Further, in the above steel pipe placing device, the stopper of the cylindrical earth removing member engages with a stopper provided in advance on the steel pipe to be placed, so that the rotational reaction force generated when the rotary drive device is operated is applied to the steel pipe. play a role in ensuring that

Also, the above purpose is
inserting the excavation shaft member of the steel pipe driving device into the steel pipe to be driven,
Connect the cylindrical earth removal member of the steel pipe placing device to the upper part of the steel pipe to be placed,
Operate the rotary drive device with the cylindrical earth removal member connected to the upper part of the steel pipes,
Place steel pipes into the target ground,
It is achieved by a steel pipe placing method characterized by:

The steel pipe placing method described above is a method of placing steel pipes using a guide material. The steel pipes are driven into the target ground while being guided by the material.

In the present invention, the cylindrical earth removing member is provided integrally with the steel pipe placing device. And this cylindrical earth removing member can be attached with any length. Also, the excavating shaft member can be attached with any length accordingly. Due to these characteristics, for example, the design position of the head of the steel pipe is in the ground or underwater during construction, and the finished pile head is better than the installation surface of means such as guide materials (which become rotational reaction force). Even at sites where the (designed pile top) is low, the above cylindrical earth removal member has a length according to the construction conditions of each site and performs various functions as a yattco, so that it can be welded to the top of steel pipes. The length of the attachment is no longer required, and the length of steel pipes (material length) can be shortened, making it economical. Furthermore, according to the present invention, troublesome work such as adding or cutting off the yattco to the steel pipes is completely unnecessary. Therefore, according to the present invention, it is possible to proceed with the placing of steel pipes economically, efficiently and safely.

Further, in the present invention, the cylindrical earth removing member provided in the steel pipe placing apparatus is configured to have approximately the same diameter (substantially the same outer diameter) as the steel pipes to be placed. As a result, when the cylindrical earth removing member of the steel pipe placing device is connected to the upper part of the steel pipes to be placed, the cylindrical earth removing member and the steel pipes are flush with each other (there is almost a step between the two). flat state). As a result, it is possible to create a pseudo-continuous state that looks as if the steel pipes are extended.
Even if there is no Yatko, it is possible to place the steel pipe head even if the design position of the steel pipe head is in the ground or in the water at the time of construction.
In addition, there is no troublesome ancillary work such as replenishment of the guide material (corresponding to the step caused by the difference in diameter between the steel pipes to be placed and the cylindrical earth removal member). In addition, a narrow clearance where a construction jig or structure is placed so as to be in contact with the outer circumference of the pile's protruding part above the ground, and which cannot be passed through with a conventional earth removal cap, making construction impossible. Even on the site where the construction conditions are limited to , the same diameter allows the cylindrical earth removal member to pass through and the steel pipes to be placed.

Further, in the present invention, the connection portion of the cylindrical earth removing member has a telescopic connection structure that can be connected to the upper portion of the steel pipes to be placed. That is, a cylindrical earth removal member having the same diameter as the steel pipes and having a rotation-preventing material is fitted and connected to the upper end of the steel pipes.
Due to these features, through a telescoping structure that can be connected to the upper part of the cylindrical earth removal member and the attached steel pipes, the rotating shaft of the rotary drive unit and the center of the steel pipes (pile center) are integrated. The excavation axis is stable, and it is easy to control the driving attitude of the steel pipes that will become piles, and it is easy to maintain verticality and straightness, resulting in a construction method that allows high-quality and safe work.
In addition, airtightness is ensured at the connection portion of the cylindrical earth discharging member, and air leakage and pressure drop due to the leakage of air at the connection portion do not occur. Therefore, even if the design position of the head of the steel pipe is underground or underwater at the time of construction, the excavated mud blown up through the steel pipe to be placed (it will surely be blown up to the top without losing momentum in the middle). , can be reliably discharged from the discharge opening of the cylindrical discharge member.

In addition, in the present invention, for example, the guide material used as a set with the steel pipe placing device has an engaging portion (for example, a concave portion) that engages with a rotation suppressing means (for example, a convex portion) provided on the steel pipe, The steel pipes have rotation restraint means (for example, recesses) that engage with engaging portions (for example, projections) of the guide material to restrain rotation of the steel pipes during driving. As a result, the guide material used in combination with the steel pipe placing device can function not only as a steel pipe guide means but also as a means for suppressing the rotation of the steel pipes.

Further, in the present invention, the cylindrical earth-discharging member of the steel pipe placing device is, for example, a rotation suppressing means (e.g., a convex portion) that engages with an engaging portion (e.g., a concave portion) of the guide material to suppress the rotation of the steel pipes. ). As a result, even after the steel pipes being placed have passed through the guide material, it is possible to secure the rotational reaction force through the engagement relationship between the cylindrical earth removal member and the guide material. Even if the design position is in the air, underground, or underwater during construction, the rotational reaction force can be secured until the completion of excavation.

In addition, in the present invention, the stopper of the cylindrical earth removing member engages with a stopper provided in advance on the steel pipe to be placed, thereby securing a rotational reaction force to the steel pipe when the rotary drive device is operated. Due to these features, even if the head of the steel pipes is lower than the guide material, the steel pipes placing device can reliably provide the necessary rotational reaction force through the cylindrical earth removal member during operation. can be secured to

It is a figure which shows an example of the steel pipes placing apparatus of this invention. Fig. 10 is a diagram showing an example of a connection mode (separated state, during fitting, during separation, or fitted state) between the cylindrical earth removing member and the steel pipe head of the steel pipe placing device. FIG. 2 is a plan view (plan view from below) showing a cylindrical earth removal member of the steel pipe placing device, and a plan view (plan view from above) showing a steel pipe pile. It is process drawing which shows the steel pipes placing method. It is a figure which shows the conventional steel pipes placing apparatus. It is a figure which shows the principle of rotary impact press-fitting of a steel pipe pile by a down-the-hole hammer. It is process drawing which shows the conventional steel pipes placing method.

A steel pipe driving device of the present invention is a device used for driving steel pipes using an excavating shaft member. Specific examples of steel pipes include steel pipe piles, steel pipe sheet piles, and casings. Hereinafter, specific embodiments of the present invention will be described, taking a steel pipe pile as a specific example of steel pipes. The conductive material used as an example in this embodiment is the same as that used in the prior art (see the right figure of FIG. 6, etc.). In the description of this embodiment, the right diagram of FIG. 6 is used.

(Steel pipe placing equipment)
First, the configuration of a steel pipe placing apparatus will be described with reference to FIGS. 1, 2, and 3. FIG.

The steel pipe driving device includes an excavating shaft member 3 having an excavating bit 2 at its tip;
a rotary drive device 5 for rotating the drilling shaft member 3;
・It has a cylindrical earth removal member 7 provided under the rotary drive device 5 so as to surround the upper part of the excavation shaft member 3 .

The rotary drive device 5 rotates the excavation shaft member 3 connected thereunder. The rotary drive device 5 is configured to be suspended by crane equipment such as a mobile crane.

The excavating shaft member 3 has a down-the-hole hammer at its lower portion, which has a built-in piston for generating an impact pressure force, as in the prior art shown in FIG. The excavating shaft member 3 is operably connected to the rotary drive device 5 through the inner side of the cylindrical earth removing member 7 . Between the outer peripheral surface of the excavating shaft member 3 and the inner peripheral surface of the cylindrical earth discharging member 7 of the steel pipe placing device, there is a gap for discharging the excavated muck (excavated soil) blown up by the air lift. there is The basic principle of the muck airlift is similar to the prior art shown in FIG.

The cylindrical earth removing member 7 is a cylindrical member having substantially the same diameter as the steel pipe pile P to be driven. That is, the outer diameters of the cylindrical earth removing member 7 and the steel pipe pile P thereunder are substantially equal. The cylindrical earth removing member 7 is fixed under the rotary drive device 5 so as to surround the upper portion of the excavating shaft member 3 and is integrated with the rotary drive device 5 . A steel pipe pile P to be driven is connected to the lower end of the cylindrical earth removing member 7 . This cylindrical earth unloading member 7 has a function equivalent to that of the conventional yattco, and also serves as an earth unloading path that guides the excavated muck blown up by the airlift through the steel pipe pile P toward the earth unloading port 71. Function.

This cylindrical earth removal member 7 is
- A discharge port 71 for discharging the excavated mud blown up through the steel pipe pile P to be driven;
An earth discharge cover 73 for guiding downward the earth discharged from the earth discharge port 71;
- A connection part 75 that enables connection of the tubular earth removal member 7 to the steel pipe pile P (see FIG. 2),
A stopper 77 that applies rotational reaction force to the steel pipe pile P when the steel pipe pile P is passing through the guide material G;
- It has a rotation restraining member 78 (engagement member) that applies a rotational reaction force to the guide material G when the cylindrical earth removing member 7 is passing through the guide material G.

The excavating shaft member 3 and the cylindrical earth-discharging member 7, which are provided approximately equal to the length of the jack, are provided so that they can be attached with arbitrary lengths. That is, the term "Yatko" as used herein refers to a structure such as having an inner space through which the excavating shaft member (3) is inserted, having an inner space serving as an earth discharge path, and supplying the rotational reaction force of the pile driving device. A member provided at the head of the steel pipes for the purpose of responding to such construction requirements, and integrally extending to the rotation drive device (5) as an extension of the steel pipe pile (P), and its device configuration and construction The length is optimized for each aspect. Therefore, the length of the wall is not particularly limited, and it may have a predetermined length, for example, as long as it can play the role of the wall for the purpose of construction according to the construction conditions, or , may have any length. Therefore, one type of yattco length may be used, or a plurality of types of variations may be prepared according to construction conditions, site conditions, and the like. In addition, for example, in the case of multiple construction such that the design (finished) height of the pile head differs for each pile, the excavation shaft member 3 has a certain length (for example, the maximum length required at the site) and has a cylindrical shape. It is also possible to configure the apparatus such that the length of the earth removing member 7 is made variable according to the conditions of the object to be worked.

A discharge cover 73 of the cylindrical discharge member is provided on the outer peripheral surface of the cylindrical discharge member 7 so as to cover the discharge port 71 . This earth discharge cover 73 plays a role of controlling the flow of the excavated muck blown out from the earth discharge port 71 so that it falls downward without being scattered around.

The connecting portion 75 of the cylindrical earth removing member (see FIG. 2) is a portion for detachably connecting the cylindrical earth removing member 7 to the upper portion of the steel pipe pile P to be driven. As shown in FIG. 2, the connecting portion 75 has a telescopic connecting structure that can be connected to the upper portion of the steel pipe pile P to be driven. The outer diameter of the cylindrical connecting portion 75 is slightly smaller than the inner diameter of the steel pipe pile P, and as shown in FIG. Alternatively, the connecting portion can be put in and taken out from the inside of the steel pipes (with a small gap). Then, in a state where they are fitted as illustrated in FIG. 2(c), the cylindrical earth removal member 7 and the steel pipe pile P are integrated.

A stopper 77 of the cylindrical earth removing member is welded to the outer peripheral surface of the cylindrical earth removing member 7 and restricts the rotational movement of the mutually connected steel pipe pile P and the cylindrical earth removing member 7 . When the steel pipe pile P passes through the guide material G, the stopper 77 applies the rotational reaction force (reaction force source of the rotational force) of the rotary drive device 5 to the steel pipe pile P (the steel pipe pile to be driven). P).

Two parallel stoppers 77 are provided on the side surface of the cylindrical earth removing member 7 so as to protrude downward from the lower end of the cylindrical earth removing member 7 . As shown in FIGS. 2 and 3, two pairs of stoppers P7 that engage with the two stoppers 77 are provided on the outer peripheral surface of the head of the steel pipe pile P at positions facing each other with the pile center therebetween. As shown in FIGS. 2(b) and 2(c), when connecting the tubular earth removal member 7 to the head of the steel pipe pile P, the steel pipe pile P is inserted between the stoppers 77 of the tubular earth removal member 7. The steel pipe pile P and the cylindrical earth removing member 7 are positioned so that the stopper P7 is inserted.
In this embodiment, as a specific example of the rotation restraint member 78 of the cylindrical earth removing member 7, two stoppers 77 provided on the side surface of the cylindrical earth removing member 7 are used. Although the stopper P7 provided on the outer peripheral surface of the head of the pile P is mentioned, the shape of the rotation restraint member is not limited to this.
That is, the stopper member provided on the cylindrical earth removal member 7 and the stopper of the steel pipe pile P can be engaged with each other, and through the engagement relationship, the rotation of the steel pipe pile P can be suppressed (for example, the cylindrical discharge member 7). By providing an engaging structure such as a notch in the connecting portion 75, which forms a telescopic connection structure with the top portion of the steel pipe attached to the soil member 7, the connecting portion 75 functions as a stopper, and the inside of the head portion of the steel pipe pile P. As long as it is provided with a stopper member that engages with the notched portion on the peripheral surface, any member can be employed as the rotation restraint member.

As shown in FIGS. 2 and 3, the rotation restraint member 78 of the cylindrical earth discharging member 7 is provided protruding from the outer peripheral surface of the cylindrical earth discharging member 7, and is composed of, for example, a bar-shaped elongated member. there is Further, a member (rotation restraining member P3) similar to the rotation restraining member 78 provided in the cylindrical earth discharging member 7 is protruded from the outer peripheral surface of the steel pipe pile P. As shown in FIG. The guiding material G used for driving the steel pipe pile P is provided with a concave portion G3 (engaging portion ) is provided. See the right figure in FIG.

In this embodiment, a "convex structure" is given as a specific example of the rotation restraint member 78 of the cylindrical earth discharging member 7, and a "concave structure" is given as a specific example of the rotation restraint member P3 of the steel pipe pile P. However, the shape of the rotation restraint member is not limited to this. That is, the rotation suppressing member 78 of the cylindrical earth discharging member 7 and the rotation suppressing member P3 of the steel pipe pile P can be engaged with each other, and the rotation suppression of the steel pipe pile P can be achieved through the engagement relationship (for example, steel pipe sheet pile As long as it is a steel member attached to a predetermined position with a length exceeding the excavation length in the longitudinal direction of the steel pipe pile P, such as a joint, any rotation restraint member can be adopted.

In the driving construction of the steel pipe pile P, when the steel pipe pile P is passing through the guide material G, the rotation suppressing member P3 of the steel pipe pile P slides in a state of being fitted with the recess G3 (engagement portion) of the guide material G. do.
On the other hand, when the steel pipe pile P passes through the guide material G and the cylindrical earth removing member 7 passes through the guide material G, the rotation restraining member 78 of the cylindrical earth removing member 7 is engaged with the recess G3 (engagement) of the guide material G. part) and slide.
Therefore, even when the guide material G guides either the steel pipe pile P or the cylindrical earth removal member 7, the rotation suppression effect (rotation prevention effect) of the guide material G is exhibited, and the rotation drive device 3 is driven through the guide material G. is ensured.

(Method for placing steel pipes)
Next, based on FIG. 4, a steel pipe driving method using the steel pipe driving apparatus having the above configuration and a guide material will be described. A steel pipe pile is given as an example of steel pipes. In the process illustrated in FIG. 4, the top of the design pile is located at a position lower than the ground height (the surface on which the guide material is installed), and the steel pipe pile is driven so that the top of the steel pipe pile to be driven reaches the top of the design pile shown. It is assumed that

As shown in FIG. 4(a), in the step of driving the steel pipe pile P, first, the drilling shaft member 3 of the steel pipe driving device is inserted into the hollow portion of the steel pipe pile P, and the drill bit 2 to set the drilling bit in the expanded state.
Further, when inserting the excavation shaft member 3 into the steel pipe pile P, the cylindrical earth removal member 7 of the steel pipe driving device is connected to the upper part of the steel pipe pile P. At this time, as shown in FIG. 2(b), the connecting portion 75 of the cylindrical earth removing member 7 is fitted into the upper inner side of the steel pipe pile P to be spigot-fitted.
Furthermore, when inserting the excavation shaft member 3 into the steel pipe pile P, as shown in FIGS. , the steel pipe pile P and the cylindrical earth removing member 7 are positioned so that the stopper P7 of the steel pipe pile enters. The rotation reaction force of the rotary drive device 5 is secured to the steel pipe pile P by the mutual engagement of the stoppers 77 and P7.
In addition, the stopper 77 is configured with the minimum wall thickness necessary for design so that it does not become a penetration resistance to the ground, corresponding to the case where the pile head is designed to be located in the ground including hard ground or bedrock. good to do
When the connecting portion 75 of the cylindrical earth removing member 7 is fitted to the inside of the upper portion of the steel pipe pile P in the manner described above and is spigot-fitted, the stepped portion at the base end of the connecting portion 75 of the cylindrical earth removing member 7 The cylindrical earth removal member 7 and the steel pipe pile P are integrated in a state where the top end of the steel pipe pile P abuts against 79 . In the integrated state as shown in FIG. 2(c), the tubular earth removal member 7 and the steel pipe pile P are connected in a flush state (flat state with almost no step between them).
By the spigot fitting, it has a structure that can be integrated so that the rotating shaft of the rotary drive device 5 and the center (pile center) of the steel pipe pile P are aligned, and the excavation shaft is firmly stabilized with the pile. It is easy to control the driving attitude of the steel pipe pile P, which makes it easy to maintain verticality and straightness, so that work can be performed safely and high quality can be ensured.
In this state, the steel pipe driving device is suspended by a crane, the steel pipe pile P is passed through the guide space of the guide material G, and the excavation bit 2 is set at the center of the pile.
For example, as shown in the right side of FIG. 6, the guide material G is composed of a combination of a plurality of steel materials such as H-shaped steel in a grid pattern or a lattice shape, and the inner space surrounded by the steel materials is a steel pipe pile. It functions as a space for guiding P. In addition, the structure of the guide material G is not necessarily limited to the one described above, and any material can be used as long as it can guide the steel pipes to be placed.

Next, the rotary driving device 5 is operated in a state where the steel pipe pile P is secured with the rotational reaction force by the stoppers 77 and P7, and as shown in FIG. are used together to advance the driving of the steel pipe pile P through the guide material G. During the process of rotary excavation and impact press-fitting, the bar-shaped rotation-preventing member P3 fixed to the outer peripheral surface of the steel pipe pile P is kept in a state of being fitted (a state of sliding engagement) with the concave portion G3 of the guide material G. The steel pipe pile P is guided in the driving direction by the guide material G.

As the impact press-fitting of the steel pipe pile P progresses, the top end of the steel pipe pile P approaches the guide material G. If the steel pipe pile P continues to be hammered and pressed in as it is, the crown of the steel pipe pile P being driven passes through the guide material G and the steel pipe pile P separates from the guide material G. A cylindrical earth removal member 7 having approximately the same diameter is connected. Therefore, unlike the earth unloading cap of the prior art, the cylindrical earth unloading member 7 in this embodiment can pass through the guide space of the guide material G as shown in FIG. 4(c). Further, on the outer peripheral surface of the cylindrical earth removing member 7, similarly to the steel pipe pile P, a rotation suppressing member 78 (e.g., a bar-shaped elongated member) is protrudingly provided on the outer peripheral surface, so that it is driven. Even if the top end of the steel pipe pile P passes through the guide material G and the steel pipe pile P is separated from the guide material G, the rotational reaction force can be secured to the guide material G via the cylindrical earth removing member 7 .

Then, as shown in FIG. 4(d), when the crown of the steel pipe pile P reaches the crown of the design pile, the connection between the cylindrical earth removal member 7 and the steel pipe pile P is released, and the steel pipes are driven from the steel pipe pile P. The installation of the steel pipe pile P is completed by pulling out the device.

According to the driving method using the steel pipe driving device described above, for example, even at a site where the finished pile head (designed pile crest) is lower than the guide material G, an uneconomical yattco shown in FIG. It eliminates the need for any troublesome work such as adding or cutting off the yattco, which has been troublesome in the past. In addition, the addition of the excavation shaft member 82, which was necessary when adding the yattco, is completely unnecessary. Therefore, according to the present invention, it is possible to drive steel pipe piles efficiently and safely.
In addition, airtightness is ensured at the connecting portion 75 of the cylindrical earth discharging member 7, and air leakage does not occur at the connecting portion. Therefore, the excavated muck blown up through the inner space of the steel pipe pile P to be driven (certainly blown up to the upper part without losing its momentum in the middle) is reliably discharged from the unloading port 71 of the cylindrical earth unloading member 7. Ejected.

In the above-described embodiment, a steel pipe pile is used as an example of steel pipes, but the steel pipes that can be driven by the present invention are not limited to this. can be applied.

2 drilling bit 3 drilling shaft member (drill rod)
5 Rotation drive device 7 Cylindrical discharge member 71 Discharge port 73 Discharge cover 75 Connecting part 77 Stopper (Means for fixing the position in the circumferential direction)
78 Rotation restraining member (engaging member)
79 stepped portion 81 rotary drive device 82 drilling shaft member (drill rod)
83 Down-the-hole hammer 84 Overhang 85 Excavation bit 87 Discharge cap Y Yatko (dummy pipe)
P Steel pipe pile (steel pipes)
P7 Stopper (means for fixing the position in the circumferential direction)
P1 Casing top P3 Rotation restraining member (engagement member)
G guide material G3 concave portion (engagement portion)

Claims (9)

an excavation shaft member having a length approximately equal to at least the length of the steel pipe plus the length of the yattco;
a drilling bit provided at the tip of the drilling shaft member;
a rotary drive device for rotating the drilling shaft member;
a cylindrical earth removal member provided under the rotary drive device so as to surround an upper portion of the excavation shaft member;
The tubular earth removal member is
It has a length that is at least approximately equal to the length of Yatko,
a connection part for detachably connecting the cylindrical earth removal member to the upper part of the steel pipes to be placed;
An excavation port for discharging excavated mud blown up through the steel pipes to be placed,
A steel pipe placing device characterized by having The tubular earth removal member has approximately the same diameter as the steel pipes to be placed,
The steel pipe placing device according to claim 1, characterized in that: The connecting portion of the cylindrical earth removing member is
It has a telescopic connection structure that can be connected to the upper part of the steel pipes to be cast.
The steel pipe placing device according to claim 1 or 2, characterized in that: The steel pipes have rotation restraint means for restraining rotation of the steel pipes.
The steel pipe driving device according to any one of claims 1 to 3, characterized in that: The cylindrical earth removal member of the steel pipe placing device has rotation restraint means for restraining rotation of the cylindrical earth discharge member,
The steel pipe placing device according to claim 4, characterized in that: The tubular earth removal member is
a stopper serving as a means for fixing the positions of the steel pipes and the rotary drive device in the rotational direction of the steel pipes placing device in the connected state with the steel pipes;
The steel pipe driving device according to any one of claims 1 to 5, characterized in that: The stopper of the tubular earth removal member is
By engaging with a stopper provided in advance on the steel pipe to be placed, a rotational reaction force is secured to the steel pipe when the rotary drive device is operated.
The steel pipe placing device according to claim 6, characterized in that: A steel pipe placing method using the apparatus according to any one of claims 1 to 7,
inserting the excavation shaft member of the steel pipe driving device into the steel pipe to be driven,
Connect the cylindrical earth removal member of the steel pipe placing device to the upper part of the steel pipe to be placed,
Operate the rotary drive device with the cylindrical earth removal member connected to the upper part of the steel pipes,
Place steel pipes into the target ground,
A steel pipe placing method characterized by: A method for driving steel pipes using a lead material,
After the upper part of the steel pipes to be placed passes through the guide material, the steel pipes are driven into the target ground while guiding the cylindrical earth removal member connected to the upper part of the steel pipes with the guide material.
The steel pipe placing method according to claim 8, characterized in that:

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